Final answer:
In "Letter from a Birmingham Jail," Dr. Martin Luther King, Jr. makes reference to the Supreme Court’s 1954 decision in Brown v. Board of Education, which supports his reason for being in Birmingham to fight for moral justice. He emphasizes the need to disobey unjust laws, in line with the philosophy of St. Augustine.
Step-by-step explanation:
The seminal document that King refers to in his "Letter from a Birmingham Jail" is the case of Brown v. Board of Education, where the Supreme Court's decision of 1954 outlaws segregation in public schools. King discusses three reasons for being in Birmingham, one of which is supported by his distinction between just and unjust laws. This pertains to his argument that not only the legalization but the moral rectitude of integration should be advocated by religious leaders, supporting his claim that his presence in Birmingham is to promote moral justice beyond legal dictates.
Dr. King concurs with St. Augustine, stating that "an unjust law is no law at all," which underscores the moral responsibility to disobey unjust laws, thereby justifying the Civil Rights Movement's strategy of civil disobedience against segregation. This is one of King's reasons for being in Birmingham: to combat unjust laws that segregate and discriminate, as he considers it a moral obligation to fight against laws that are immoral in nature.